Channel Selector for a Radio Frequency Receiver

1. A channel (C 0 ) selector ( 1 ) for a frequency-modulation radiofrequency receiver, comprising a bandpass filter ( 2 ), the frequency band (BPF) of which is centered on the center frequency (F 0 ) of the channel (C 0 ) to be selected and has a width that is variable automatically between a minimum value (MinBP) and a maximum value (MaxBP), the minimum value (MinBP) being determined dynamically in proportion to a weighted sum of the field level (C) and the modulation level (M) of the channel (C 0 ), in accordance with a formula MinBW=k1×C+k2×M, where MinBW is the minimum value, C is the field level, k1 is the weight associated with the field level (C), M is the modulation level, and k2 is the weight associated with the modulation level (M), wherein the weight (k1) associated with the field level (C) is lower than the weight (k2) associated with the modulation level (M).

2. The selector ( 1 ) as claimed in claim 1 , wherein the field level (C) and/or the modulation level (M) are measured on a measurement frequency band (BPM) equal to the frequency band of the filter (BPF).

3. The selector ( 1 ) as claimed in claim 2 , wherein the maximum value (MaxBP) is constant and equal to the total modulation range (EMT) of the channel (C 0 ).

4. The selector of claim 3 , wherein the maximum value (MaxBP) is also equal to the useful modulation range (EMU) of the channel (C0).

5. The selector ( 1 ) as claimed in claim 2 , wherein the minimum value (MinBP) is increased by way of a maximum boundary (Bmax) equal to the maximum value (MaxBP) and decreased by way of a minimum boundary (Bmin).

6. A radiofrequency receiver comprising the channel selector ( 1 ) as claimed in claim 2 .

7. The selector ( 1 ) as claimed in claim 1 , wherein the maximum value (MaxBP) is constant and equal to the total modulation range (EMT) of the channel (C 0 ).

8. The selector of claim 7 , wherein the maximum value (MaxBP) is also equal to the useful modulation range (EMU) of the channel (C 0 ).

9. The selector ( 1 ) as claimed in claim 7 , wherein the minimum value (MinBP) is increased by way of a maximum boundary (Bmax) equal to the maximum value (MaxBP) and decreased by way of a minimum boundary (Bmin).

10. The selector of claim 9 , wherein the maximum value (MaxBP) is also equal to the useful modulation range (EMU) of the channel (C0).

11. A radiofrequency receiver comprising the channel selector ( 1 ) as claimed in claim 7 .

12. The selector ( 1 ) as claimed in claim 1 , wherein the minimum value (MinBP) is increased by way of a maximum boundary (Bmax) equal to the maximum value (MaxBP) and decreased by way of a minimum boundary (Bmin).

13. The selector of claim 12 , wherein the minimum boundary (Bmin) is between half and double a minimum value (MinBP0) of between 30 and 50 kHz.

14. The selector of claim 12 , wherein the minimum boundary (Bmin) is equal to a minimum value (MinBP0) of between 30 and 50 kHz.

15. A radiofrequency receiver comprising the channel selector ( 1 ) as claimed in claim 12 .

16. A radiofrequency receiver comprising the channel selector ( 1 ) as claimed in claim 1 .

17. The selector of claim 1 , wherein a ratio of the weight (k1) associated with the field level (C) to the weight (k2) associated with the modulation level (M) is 1:3.

18. The selector ( 1 ) as claimed in claim 17 , wherein the field level (C) and/or the modulation level (M) are measured on a measurement frequency band (BPM) equal to the frequency band of the filter (BPF).

19. The selector ( 1 ) as claimed in claim 17 , wherein the maximum value (MaxBP) is constant and equal to the total modulation range (EMT) of the channel (C0).

20. The selector ( 1 ) as claimed in claim 17 , wherein the minimum value (MinBP) is decreased by way of a maximum boundary (Bmax) equal to the maximum value (MaxBP) and increased by way of a minimum boundary (Bmin).